Mesogenic acrylate copolymers having both siloxy and alkylene spacer groups

ABSTRACT

The present invention relates to a copolymer consisting of a polyacrylate type backbone having mesogenic groups in the side chains, which comprises an acrylate type repeating unit (I) wherein a mesogenic group is bonded by an ester linkage via an alkylene chain, and an acrylate type repeating unit (II) wherein a mesogenic group is bonded by an ester linkage via an alkylene chain containing a siloxane bond; the molar ratio of the repeating unit of the formula (I) to the repeating unit of the formula (II) ranging from 95/5 to 20/80 and the number average molecular weight being at least 1,000. The copolymer of the present invention exhibits liquid crystallinity at a relatively low temperature, i.e., around a room temperature. Accordingly, the polymer is useful for a display material of a large area, a light-shuttering material and a light-controlling glass material.

TECHNOLOGICAL FIELD

The present invention relates to a copolymer comprising a repeating unitwherein a backbone structure and a mesogenic group are bonded by meansof a spacer consisting of an alkylene chain, and a repeating unitwherein a backbone structure and a mesogenic group are bonded by meansof a spacer containing a flexible siloxane bond. More specifically, thepresent invention relates to a copolymer having a mesogenic group in theside chain comprising a repeating unit represented by the followingformula (I) and a repeating unit represented by the following formula(II), wherein molar ratio of the repeating unit of the formula (I) tothe repeating unit of the formula (II) ranges from 95/5 to 20/80 and thenumber average molecular weight is at least 1,000. ##STR1## wherein,each of R and R' which may be the same or different, is a hydrogen atom,a halogen atom, an alkyl group, or a phenyl group, each of R¹ to R⁶,which may be the same or different, is an alkyl group or a phenyl group,X is a single bond, an oxygen atom, or a group of the formula--COO--or--OCO--, each of Q¹ and Q², which may be the same or different, is amesogenic group, k is an integer of from 2 to 20, each of m and p is aninteger of from 2 to 10, and n is an integer of from 0 to 10.

BACKGROUND ART

Heretofore, side chain liquid crystalline polymers having mesogenicgroups in the side chains have been studied for a wide range ofapplications as functional materials for display elements or recordingmaterials in the electronics field or recently as functional materialsuseful for nonlinear optical materials or light-controlling glass. Theseside chain liquid crystalline polymers have a structure in whichmesogenic groups are bonded to the polymer backbone by means of aspacer.

As the backbone structure, polymers such as polymethacrylate,polyacrylate, polyether, polyorganosiloxane and polyester are known, andmany side chain liquid crystalline polymers have been proposed (Forexample, Liquid Crystal Polymer, CMC, edit. by Naoyuki Koide (1987); R.Zentel, "Liquid Crystalline Polymers", Kem. Ind., Vol. 37, p. 355(1988); V. P. Shibaev, "Synthesis and Structure of Liquid-crystallineside-chain polymers", Pure & Appl. Chem. Vol. 57, p. 1589 (1985); T.Chung, "The Recent Developments of Thermotropic Liquid CrystallinePolymers", Polym. Eng. Sci., Vol. 26, p. 901 (1986)).

Further, it has been reported that by means of a spacer, the mobility ofthe backbone structure and that of the mesogenic groups tend to beindependent, whereby orientation of liquid crystals will be facilitated,and by means of a long spacer or a more flexible spacer, a more stableliquid crystalline phase can be obtained (Naoyuki Koide, "Synthesis ofPolymer Liquid Crystals", Kobunshi, Vol. 36, p. 98 (1987)). Heretofore,most of the chemical bonds known as such spacers are alkylene groups oroxyalkylene groups. It is reported a spacer containing a siloxanecomponent which is known as a flexible chemical bond (EP-0471577-A; Y.Nagase and Y. Takamura, Makromol. Chem., Vol. 193, p. 1225 (1992)).

However, when spacers consisting of alkylene groups alone are used forthe above mentioned backbone structures, the temperatures at whichpolymers show liquid crystalline phase are usually high, and in mostcases, they show no liquid crystalline phase but glass phase attemperatures around room temperature. Further, the side chain liquidcrystalline polymers containing siloxane components in the spacerpossess problems that synthesis of the monomers requires many steps andalso high cost owing to employment of expensive silane compounds, thoughthey show liquid crystalline phase at relatively low temperature becauseof the flexibility of the siloxane bonds.

In view of such a drawback of side chain liquid crystalline polymershaving conventional spacers, it is an object of the present invention toprovide a side chain liquid crystalline polymer which exhibits stableliquid crystalline phase at a relatively low temperature, i.e., at roomtemperature or a lower temperature, by utilizing more effectively amonomer containing a siloxane component in the spacer.

DISCLOSURE OF INVENTION

The present inventors have conducted extensive researches on effectiveutilization of a monomer containing a siloxane component in order tosynthesize a side chain liquid crystalline polymer which show liquidcrystalline phase at a practical low temperature. As a result, they havefound that a copolymer exhibiting liquid crystalline phase at relativelylow temperature can be synthesized by copolymerization of a monomerwherein a backbone structure and a mesogenic group are bonded by meansof a siloxane bond with a conventional monomer having a spacerconsisting of an alkylene chain alone. The temperature is almost thesame level as the temperature at which a corresponding homopolymer ofthe former monomer exhibits liquid crystalline phase. The presentinvention has been accomplished on the basis of these discoveries.

Namely, the present invention provides a copolymer having a mesogenicgroup in the side chain comprising a repeating unit represented by thefollowing formula (I): ##STR2## wherein, R is a hydrogen atom, a halogenatom, an alkyl group or a phenyl group, X is a single bond, an oxygenatom or a group of the formula --COO--or --OCO--, Q¹ is a mesogenicgroup, and k is an integer of from 2 to 20, and a repeating unitrepresented by the following formula (II): ##STR3## wherein, R', whichmay be the same or different to the above R, is a hydrogen atom, ahalogen atom, an alkyl group or a phenyl group, each of R¹ to R⁶, whichmay be the same or different, is an alkyl group or a phenyl group, X isa single bond, an oxygen atom or a group of the formula --COO--or--OCO--, Q² which may be the same or different to the above Q¹, is amesogenic group, each of m and p is an integer of from 2 to 10, and n isan integer of from 0 to 10; and the molar ratio of the repeating unit ofthe formula (I) to the repeating unit of the formula (II) ranges from95/5 to 20/80 and the number average molecular weight is at least 1,000.

The mesogenic group represented by Q¹ and Q² in the above formulas (I)and (II) is a known liquid crystallinity-imparting group, and there isno particular restriction as to its structure. The mesogenic groupincludes a group which is formed by removing one hydrogen atom from amesogen molecule such as biphenyl, biphenyl ether, phenyl benzoate,biphenyl benzoate, benzylideneaniline, stilbene, azoxybenzene,azobenzene, a schiff base, cyclohexyl phenyl ether, cyclohexylbenzene,phenyl cyclohexanecarboxylate, biphenyl cyclohexanecarboxylate,cholesterol, cholestane or a derivative thereof. Further, a polar groupsuch as an alkyl having an optically active group, alkoxy group, afluoroalkyl group, a cyanoalkyl group or a cyanoalkoxy group may bebonded to the above mesogen molecule, so that a special effect such as aferroelectric nature be imparted to the polymer prepared according tothe method of the present invention.

The substituent represented by each of R and R' in the above formulas(I) and (II) may, for example, be a hydrogen atom, a halogen atom suchas fluorine, chlorine, bromine or iodine, a linear or branched alkylgroup such as a methyl group, an ethyl group, a propyl group, aniso-propyl group, a butyl group, a t-butyl group or a hexyl group, or aphenyl group. However, the substituent represented by the R ispreferably a hydrogen atom, a halogen atom, or a methyl group from theviewpoint of easiness in the synthesis.

The substituent for each of R¹ to R⁶ in the above formulas (I) and (II)may, for example, be a linear or branched alkyl group such as a methylgroup, an ethyl group, a propyl group, an iso-propyl group, a butylgroup, a iso-butyl group, a t-butyl group, pentyl group or a hexylgroup, or a phenyl group. However, a methyl group is most preferredamong the above substituents, from the viewpoint of easiness in thesynthesis and in order to make the best use of the characteristics ofthe polymer having a mesogenic group of the present invention. Themethylene chain in the above formulas (I) and (II) is required to have acertain length. Accordingly, in the formulas, the number of methylenegroups represented by k is within a range of from 2 to 20, and thenumber of methylene groups represented by each of m and p is within arange of from 2 to 10. However, each of m and p is more preferablywithin a range of from 3 to 6 from the viewpoint of easiness in thesynthesis and in order to make the best use of the characteristics ofthe polymer mesogenic groups of the present invention. Further, thenumber of siloxane units represented by n in the formula (II) is withina range of from 0 to 10, and is more preferably within a range of from 0to 5 from the viewpoint of easiness in the synthesis and in order tomake the best use of the characteristics of the side chain liquidcrystalline polymer of the present invention.

The copolymer of the present invention is obtained by mixing andpolymerizing a monomer represented by the following formula (III):##STR4## wherein, R is a hydrogen atom, a halogen atom, an alkyl group,or a phenyl group, X is a single bond, an oxygen atom, or a group of theformula --COO--or --OCO--, Q1 is a mesogenic group, and k is an integerof from 2 to 20; and a monomer represented by the following generalformula (IV): ##STR5## wherein, R', which may be the same or differentto the above R, is a hydrogen atom, a halogen atom, an alkyl group or aphenyl group, each of R¹ to R⁶, which may be the same or different, isan alkyl group or a phenyl group, X is a single bond, an oxygen atom ora group of the formula --COO--or --OCO--, Q² is a mesogenic group, eachof m and p is an integer of from 2 to 10, and n is an integer of from 0to 10. At the copolymerization, a known addition polymerization methodsuch as radical polymerization, anionic polymerization or cationicpolymerization, may be employed. However, in this case, radicalpolymerization is preferably employed as the preferably employed as thesimplest method. When the polymerization is conducted by the radicalpolymerization method, a known method such as bulk polymerizationmethod, solution polymerization or emulsion polymerization, may beemployed. The radical polymerization may simply be initiated by heating,irradiation with ultraviolet rays or addition of a radical initiator. Asthe radical initiator which can suitably be employed for the reaction,an organic peroxide such as dilauroyl peroxide, di-t-butyl peroxide,benzoyl peroxide, t-butyl hydroperoxide or cumene hydroperoxide, or anazo compound such as α,α'-azobisisobutyronitrile orazobiscyclohexanecarbonitril, may be mentioned.

Further, the molecular weight of the resulting polymer can be controlledto some extent by adding a chain transfer agent during thepolymerization. As the chain transfer agent to be used here, carbontetrachloride, bromotrichloromethane, p-benzoquinone, chloroanile,n-butanethiol, n-dodecanethiol or the like, may be mentioned. As theorganic solvent to be used for the radical polymerization, it ispossible to employ benzene, toluene, chlorobenzene, tetrahydrofuran,chloroform, methyl ethyl ketone, fluorobenzene, methanol, ethanol, n- ori-propanol, N,N-dimethylformamide or N,N-dimethylacetamide. However, thesolvent is not limited to such specific examples. The reaction usuallyproceeds smoothly within a temperature range of from 40° to 100° C.

The monomer represented by the above formula (III) is a known compoundand the preparation is described in many literatures, for example, H.Finkelmann, H. Ringsdorf and J. H. Wendorff, Makromol. Chem., Vol. 179,p. 273 (1978); R. Zentel and H. Ringsdorf, Makromol. Chem., RapidCommun., Vol. 5, p. 393 (1984); V. Shibaev and N. Plate, Pure and Appl.Chem., Vol. 57, p. 1589 (1985); C. S. Hsu and V. Percec, J. Polym. Sci.,Polym. Chem. Ed., Vol. 26, p. 2047 (1988); Vol. 27, 453 (1989).

The monomer of the above formula (IV) can be prepared, for example,according to the following synthetic methods.

The following method can be used in a case where the degree ofpolymerization of the siloxane chain represented by n in the aboveformula (IV) is 0, i.e., in a case where a monomer wherein apolymerizable group and a mesogenic group are bonded by means of aspacer containing a disiloxane bond, is to be prepared. Namely, thedesired monomer can be prepared by reacting a silanol compound having amesogenic group, of the following formula (V) ##STR6## wherein, each ofR⁵ and R⁶, which may be the same or different, is an alkyl group or aphenyl group, X is a single bond, an oxygen atom or a group of theformula --COO--or --OCO--, Q² is a mesogenic group, and p is an integerof from 2 to 10; with a chlorosilane compound having a polymerizablegroup, of the following formula (VI) ##STR7## wherein, R' is a hydrogenatom, a halogen atom, an alkyl group or a phenyl group, each of R¹ andR² which may be the same or different, is an alkyl group or a phenylgroup, and m is an integer of from 2 to 10.

When the silanol compound of the above formula (V) is reacted with thechlorosilane compound of the above formula (VI), hydrogen chloride willbe generated. Therefore, the reaction is preferably conducted in thepresence of an organic base such as triethylamine, N,N-dimethylanilineor pyridine as a scavenger so that the reaction proceeds smoothly. Thisreaction is preferably conducted in an organic solvent. Here, as such asolvent, tetrahydrofuran, benzene, toluene, n-hexane, chloroform, carbontetrachloride or the like, may preferably be used. Further, the reactionis preferably conducted in an atmosphere of an inert gas such as argonor nitrogen. The chlorosilane compound of the above formula (VI) to beused here, includes, for example, 2-(acryloxy)ethyldimethylchlorosilane,2(methacryloxy)ethyldimethylchlorosilane,2-(α-ethylacryloxy)ethyldimethylchlorosilane,2-(α-butylacryloxy)ethyldimethylchlorosilane,2-(α-chloroacryloxy)ethyldimethylchlorosilane,2-(α-fluoroacryloxy)ethyldimethylchlorosilane,2-(α-cianoacryloxy)ethyldimethylchlorosilane,2-(α-phenylacryloxy)ethyldimethylchlorosilane, 3-(acryloxy)-propyldimethylchlorosilane,3-(methacryloxy)propyldimethylchlorosilane,3-(α-butylacryloxy)propyldimethylchlorosilane,3-(α-butylacryloxy)propyldimethylchlorosilane,3-(α-fluoroacryloxy)propyldimethylchlorosilane,3-(cyanoacryloxy)propyldimethylchlorosilane,3-(α-phenylacryloxy)propyldimethylchlorosilane,4-(methacryloxy)butyldimethylchlorosilane,5-(methacryloxy)pentyldimethylchlorosilane,6-(methacryloxy)hexyldimethylchlorosilane,3-(methacryloxy)propyldiethylchlorosilane,3-(methacryloxy)propyldibutylchlorosilane,3-(methacryloxy)propyldihexylchlorosilane,3-(methacryloxy)propylmethylbutylchlorosilane,3-(methacryloxy)propylmethylhexylchlorosilane,3-(methacryloxy)propylmethylphenylchlorosilane,3-(methacryloxy)propyldiphenylchlorosilane. Some of these compounds arecommercially available. Further, the compounds can be prepared byhydrosilylation of a corresponding alkenyl ester of α-substituted orunsubstituted acrylic acid with a diorganochlorosilane.

In a case where the polymerization degree of the siloxane chainrepresented by n in the above formula (IV) is at least 1, i.e., in acase where a monomer in which a polymerizable group and a mesogenicgroup are bonded by means of a spacer containing a polysiloxane bond isto be prepared, the following method can be employed. Namely, themonomer can be prepared by reacting the silanol compound of the aboveformula (V) with a dichloro compound of the following formula (VII):##STR8## wherein, each of R³ to R⁶ which may be the same or different,is an alkyl group or a phenyl group and n is an integer of from 0 to 10;and then reacted with a silanol compound having a polymerizable group,of the following formula (VIII): ##STR9## wherein, R' is a hydrogenatom, a halogen atom, an alkyl group or a phenyl group, each of R¹ andR² which may be the same or different, is an alkyl group or a phenylgroup, and m is an integer of from 2 to 10.

At the reaction, it is preferred to employ at least two molar equivalentof the dichloro compound of the above formula (VII) relative to thesilanol compound having a mesogenic group, of the above formula (V).Further, the reaction is preferably conducted by diluting the compoundof the above formula (V) with an organic solvent. As the organic solventto be used here, it is suitable to employ hexane, heptane, diethylether, ethyl acetate, benzene, toluene, xylene, chloroform,dichloromethane, dichloroethane, acetone, tetrahydrofuran or the like.However, the solvent is not limited to such specific examples. Further,it is preferred to conduct the reaction under cooling at around 0° C. inview of suppressing side-reactions. In this reaction, hydrogen chloridewill be generated. Therefore, the reaction is preferably conducted inthe presence of an organic base such as triethylamine,N,N-dimethylaniline or pyridine as a scavenger so that the reactionproceeds smoothly.

When the desired monomer is prepared by reacting the silanol compoundhaving a polymerizable group, of the above formula (VIII) directly afterthe above reaction, it is preferred to remove remaining dichlorocompound from the reaction media by evaporation. Also, the reaction ispreferably conducted in an organic solvent and the above solvents arepreferably employed. In this reaction, hydrogen chloride will also begenerated. Therefore, the reaction smoothly proceeds in the presence ofan organic base such as triethylamine, N,N-dimethylaniline or pyridineas a scavenger.

The dichloro compound of the above formula (VII) to be used at the abovepreparation, includes, for example, dichlorodimethylsilane,dichlorodiethylsilane, dichlorodipropylsilane, dichlorodibutylsilane,dichlorodiisopropylsilane, dichlorodihexylsilane,dichloromethylethylsilane, dichloromethylphenylsilane,dichlorodiphenylsilane, 1,3-dichlorotetramethyldisiloxane,1,3-dichlorotetraethyldisiloxane, 1,3-dichlorotetraphenyldisiloxane,1,5-dichlorohexamethyltrisiloxane, 1,7-dichlorooctamethyltetrasiloxane,1,9-dichlorodecamethylpentasiloxane,1,11-dichlorododecamethylhexasiloxane, and the like. These compounds arecommercially available.

Further, the silanol compound having a polymerizable group, of the aboveformula (VIII) can be prepared, for example, according to the followingmethod. Namely, the chlorosilane compound having a polymerizable group,of the above formula (VI) is dissolved in an organic solvent and isreacted with an excess water or water containing an organic solvent toobtain the silanol compound having a polymerizable group, of the aboveformula (VIII). As the organic solvent to be used here, it is possibleto employ hexane, heptane, diethyl ether, ethyl acetate, benzene,toluene, xylene, chloroform, dichloromethane, dichloroethane, acetone,tetrahydrofuran and the like. However, the solvent is not limited tosuch specific examples. Further, the reaction is preferably conductedunder cooling at around 0° C. in view of suppressing side-reactions.

The silanol compound having a mesogenic group, of the above formula (V),which is used in the process for preparing the monomer of the aboveformula (IV) may be synthesized, for example, according to the followingmethod. Namely, an alkenyl compound having a mesogenic group, of thefollowing formula (IX): ##STR10## wherein, X is a single bond, an oxygenatom, or a group of the formula --COO--or --OCO--, Q² is a mesogenicgroup, and p is an integer of from 2 to 10; and an alkoxysilane compoundof the following formula (X): ##STR11## wherein, each of R⁵ and R⁶,which may be the same or different, is an alkyl group or a phenyl group,and A is an alkyl group; are reacted in the presence of ahydrosilylation catalyst to obtain a compound of the following formula(XI): ##STR12## wherein, each of R⁵ and R⁶, which may be the same ordifferent, is an alkyl group or a phenyl group, A is an alkyl group, Xis a single bond, an oxygen atom or a group of the formula --COO--or--OCO--, Q² is a mesogenic group, and p is an integer of from 2 to 10;and the compound of the above formula (XI) is then hydrolyzed to obtaina silanol compound having a mesogenic group, of the above formula (V).

As the hydrosilylation catalyst to be used for the reaction of thealkenyl compound of the above formula (IX) and the alkoxysilane compoundof the above formula (X) to obtain the compound of the above formula(XI) in the above process, it is most common to employ a platinum typecatalyst such as platinum, platinum-carbon, chloroplatinic acid ordicyclopentadienylplatinum dichloride. However, it is also possible toemploy a metal complex containing palladium or rhodium. For example,(Ph₃ P)₄ Pd, (Ph₃ P)₂ PdC₂, (PhCN)₂ PdCl₂, (Ph₃ P)₃ RhCl, (Ph₂ PH)₂RhCl, (Ph₃ P)₂ (CO)RhCl, or [(C₂ H₅)₃ P]₂ (CO) RhCl may be used as thecatalyst. The catalyst may be used usually in an amount of from 1/100 to1/1,000 equivalent relative to the alkenyl compound of the above formula(IX). To complete the reaction, it is necessary to mix the reactants sothat the compound of the above formula (X) would be at least equimolarto the compound of the above formula (IX). This reaction is preferablyconducted in a solvent. As such a solvent, hexane, benzene, toluene,acetone, trichloroethylene, carbon tetrachloride, tetrahydrofuran or thelike, may be employed. The reaction is conducted usually at atemperature within a range of from 40° to 100° C., and preferablyconducted in an atmosphere of an inert gas such as argon or nitrogen.

The synthesis of the alkenyl compound having a mesogenic group, of theabove formula (IX) can be readily be accomplished by introducing analkenyl group directly to the above mesogenic group or by introducing analkenyl group in one of the steps for synthesizing the above mesogenicgroup, as will be described in Examples.

The alkoxysilane compound of the above formula (X) includes, forexample, dimethylmethoxysilane, dimethyethoxysilane,dimethylpropoxysilane, dimethylisopropoxysilane, diethylethoxysilane,dipropylethoxysilane, dibutylethoxysilane, dihexylethoxysilane,methylethylethoxysilane, methylphenylethoxysilane, diphenylethoxysilane.Some of these compounds are commercially available and the compounds caneasily be prepared by condensation of a corresponding commerciallyavailabe chlorosilane with an alcohol.

The hydrolysis for the preparation of the silanol compound of the aboveformula (V) from the compound of the above formula (XI) is conductedusually in the presence of a basic or acidic substance, whereby thereaction proceeds smoothly. As the basic or acidic substance to be used,it is preferred to employ a basic substance such as lithium hydroxide,potassium hydroxide, sodium hydroxide, aluminum hydroxide, potassiumcarbonate, sodium carbonate, potassium acetate or sodium acetate, or anacidic substance such as hydrochloric acid, sulfuric acid, nitric acid,acetic acid, calcium sulfate, calcium nitrate or magnesium sulfate. Whena bond susceptible to hydrolysis such as an ester bond is present in themesogenic group Q² in the above formula (XI), it is preferred to employa weakly basic substance or a weakly acidic substance among the abovementioned basic or acidic substances. Such a basic or acidic substanceis used preferably within a range of from 0.1 to 5.0 equivalent to thecompound of the above formula (XI).

Further, it is necessary to conduct this reaction in the presence ofwater. When the compound of the above formula (XI) is insoluble inwater, an organic solvent soluble in water, such as methanol, ethanol,propanol, acetone, tetrahydrofuran or acetonitrile, may be used incombination, so that the reaction proceeds smoothly. The reaction canusually be conducted at around room temperature. If the temperature ishigh, a disiloxane compound which is a dimer of the desired silanol, maysometimes be formed as a by-product. In a case where such a dimerizationis likely to proceed, it is necessary to control the reactiontemperature within a range of from -100° C. to room temperature in orderto suppress the formation of the by-product as little as possible.

In the copolymer having a mesogenic group, of the present invention, themolar ratio of the repeating unit of the above formula (I) to therepeating unit of the above formula (II) ranges from 95/5 to 20/80,preferably from 90/10 to 40/60, more preferably from 80/20 to 50/50.When the content of the repeating unit of the above formula (II) is lessthan the above lower limit, the glass transition temperature of theresulting copolymer becomes high and, as a result, the liquidcrystalline temperature range shifts to high temperature region. Whenthe content of the repeating unit of the above formula (II) is more thanthe above upper limit, the resulting copolymer tend to resist formationof liquid crystalline phase, and the monomer containing siloxanecomponent in the spacer cannot be effectively utilized. The above molarratio, i.e., the composition of the copolymer can easily be controlledby changing the feed ratio of the monomer of the above formula (III) tothe monomer of the above formula (IV) at the above polymerization.Further, the number average molecular weight of the copolymer of thepresent invention is preferably not less than 1,000 in order to make thebest use of the characteristics of polymer. The molecular weight isdetermined according to a known method such as gel permeationchromatography, osmotic pressure method, light-scattering method,viscosity method, or the like.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention will be described in further detail withreference to Reference Examples, Working Examples, and ComparativeExamples. However, it should be understood that the present invention isby no means restricted to such specific Examples.

Reference Example 1

Synthesis of monomers having an alkylene spacer ##STR13##

With 100 ml of 2-butanone were mixed 20.0 g (79.6 mmol) of11-bromoundecane-1-ol, 11.0 g (72.5 mmol) of methyl p-hydroxybenzoate,and 10.0 g (72.4 mmol) of potassium carbonate. The whole was refluxedfor 48 hours. Upon cooling the reaction mixture to room temperature, alarge amount of precipitate appeared. The precipitate was collected byfiltration under washing with hexane and dried to obtain 20.2 g ofmethyl p-(11-hydroxyundecyloxy)benzoate (1) (yield: 86.7%).

¹ H-NMR, δ (CDCl₃, ppm); 1.00-1.90 (m, 18H), 3.60 (m, 2H), 3.88 (s, 3H),4.00 (t, 2H), 6.89 (d, 2H, J═9.0Hz), 7.98 (d, H, J═9.0Hz).

IR (KBr, cm⁻¹); 3330 (--OH), 2910, 2890, 1720, 1605 (C═O), 1505, 1430,1310, 1280, 1255, 1165, 1105, 1012, 842, 760, 695.

The resulting 20.2 g (65.6 mmol) of the compound (1) was dissolved in 50ml of methanol and 50 ml of acetone. After addition of a solution of 14g of sodium hydroxide in 100 ml of water to the above solution, thewhole was refluxed for 2 hours. Upon removing the solvent byevaporation, the obtained white solid was dissolved in water. Whiteprecipitate was formed when hydrochloric acid was added until thesolution became acidic, and was collected by filtration. The precipitatewas thoroughly washed with water and dried to obtain 19.1 g ofp-(11-hydroxyundecyloxy)benzoic acid (2) (yield: 98.5%).

¹ H-NMR, δ (CDC₃, ppm); 1.20-2.00 (m, 18H), 3.62 (t, 2H), 4.00 (t, 2H),6.90 (d, 2H, J═9.0Hz), 8.01 (d, 2H, J═9.0Hz). IR (KBr, cm⁻¹); 3430(--OH), 2910, 2850, 2670, 2550, 1670 (C═O), 1602, 1435, 1302, 1248,1162, 1140, 840, 762, 640.

In 200 ml of chloroform were dissolved 15.0 g (48.6 mmol) of thecompound (2), 60.0 g (697 mmol) of methacrylic acid, 2.0 g ofp-toluenesulfonic acid, and 3.0 g of hydroquinone as polymerizationinhibitor. The whole was refluxed for 13 hours under removing waterformed. Then, after removal of solvent, the reaction mixture was pouredinto a plenty of ice-water, and the resulting precipitate was collectedby filtration and dried after washing with water. The obtained whitesolid was recrystallized from acetone to obtain 14.5 g ofp-(11-methacryloxyundecyloxy)benzoic acid (3) (yield: 78.9%).

¹ H-NMR, δ (CDC₃, ppm); 1.00-1.90 (m, 18H), 1.94 (s, 3H), 4.02 (t, 2H,J═6.2Hz), 4.14 (t, 2H, J═6.2Hz), 5.53 (s, 1H), 6.09 (s, 1H), 6.92 (d,2H, J═9.0Hz), 8.03 (d, 2H, J═9.0Hz).

IR (KBr, cm⁻¹); 2915, 2848, 2660, 2550, 1700, 1680 (C═O), 1630, 1600,1425, 1250, 1168, 768, 640.

Polyphosphoric acid ester (hereinafter referred to PPE) was obtained asa viscous colorless liquid by adding 100 ml of chloroform and 200 ml ofdiethyl ether to 90 g of phosphorus pentachloride, and refluxing thewhole at 60° C. for 2 days under argon atmosphere, followed by removalof the solvent. The compound (3) obtained as above and an equimolaramount of 4-butoxyphenol, 4-cyanophenol, 4-butoxy-4'-hydroxybiphenyl,4-octoxy-4'-hydroxybiphenyl or S-2-methylbutyl 4-hydroxybenzoate weremixed and dissolved in chloroform, respectively. Then, an excess PPE wasadded to each solution and each resulting mixture was stirred at roomtemperature for 24 hours. After completion of the reaction, water andmethylene chloride were added to each mixture and the organic phase wasrecovered. Removal of the solvent and purification by columnchromatography afforded desired monomers (4) to (8). The following showtheir yields and spectral data.

Monomer (4): Yield; 58.4%.

¹ H-NMR, δ (CDC₃, ppm); 1.00 (t, 3H), 1.20-2.10 (m, 22H), 3.90-4.30 (m,6H), 5.53 (s, 1H), 6.09 (s, 1H), 6.91-7.12 (m, 6H), 8.12 (d, 2H,J═8.8Hz).

IR (KBr, cm⁻¹); 2910, 2850, 1710 (C═O), 1602, 1472, 1260, 1192, 1166,1070, 810.

Monomer (5): Yield; 74.8%.

¹ H-NMR, δ (CDCl₃, ppm); 1.20-1.95 (m, 18H), 2.90 (s, 3H), 4.03 (t, 2H),4.12 (t, 2H), 5.52 (s, 1H), 6.07 (s, 1H), 6.96 (d, 2H, J═9.0Hz), 7.33(d, 2H, J═8.8Hz), 7.72 (d, 2H, J═9.0Hz), 8.10 (d, 2H, J═8.8Hz).

IR (KBr, cm⁻¹); 2910, 2850, 2225 (-CN), 1738, 1710 (C═O), 1632, 1600,1510, 1252, 1212, 1162, 1065, 755, 548.

Monomer (6): Yield; 47.6%. ¹ H-NMR, δ (CDCl₃, ppm); 0.99 (t, 3H),1.20-2.10 (m, 22H), 4.05-4.32 (m, 6H), 5.53 (s, 1H), 6.09 (s, 1H), 6.96(d, 4H, J═8.6Hz), 7.23 (2H, d, J═8.6Hz), 7.50 (d, 2H, J═8.8Hz), 7.57 (d,2H, J═8.6Hz), 8.15 (d, 2H, J═9.0Hz).

IR (KBr, cm⁻¹); 2915, 2845, 1722, 1704 (C═O), 1636, 1604, 1512, 1496,1470, 1318, 1282, 1260, 1210, 1164, 1080, 1038, 818.

Monomer (7): Yield; 62.9%.

¹ H-NMR, δ (CDCl₃, ppm); 0.89 (t, 3H), 1.11-2.15 (m, 30H), 3.90-4.20 (m,6H), 5.53 (s, 1H), 6.09 (s, 1H), 6.96 (d, 4H, J═8.4Hz), 7.23 (d, 2H,J═8.6Hz), 7.50 (d, 2H, J═8.6Hz), 7.57 (d, 2H, 8.6Hz), 8.15 (d, 2H,J═8.8Hz).

IR (KBr, cm⁻¹); 2910, 2850, 1722, 1702 (C═O), 1638, 1608, 1580, 1512,1496, 1470, 1398, 1398, 1318, 1260, 1216, 1192, 1166, 1080, 1038, 818.

Monomer (8): Yield; 60.4%. ¹ H-NMR, (CDCl3, ppm); 0.81-2.22 (m, 27H),1.94 (s, 3H), 3.40 (t, 2H, J═8.2Hz), 4.06 (t, 2H, J═6.3Hz), 4.00-4.45(m, 2H), 5.46 (s, 1H), 6.02 (s, 1H), 6.89 (d, 2H, J═9.0Hz), 7.21 (d, 2H,J═8.8Hz), 8.04 (d, 2H, J═8.8Hz), 8.06 (d, 2H, J═8.8Hz) .

IR (KBr, cm⁻¹); 2950, 2850, 1740, 1710 (C═O), 1600, 1510, 1470, 1300,1250, 1200, 1160, 1100, 1050, 1030, 1000, 940, 810.

Reference Example 2

Synthesis of a monomer having an alkylene spacer ##STR14##

A solution of 0.10 g (0.51 mmol) of 4-cyano-4'-hydroxybiphenyl and 0.10g (0.72 mmol) of potassium carbonate dissolved in 4 ml of 2-butanone wasrefluxed. After addition of 0.10 g (0.55 mmol) of 6-bromohexan-1-ol tothe reaction mixture, the whole was refluxed overnight. After removal ofthe solvent by distillation, water was added to the residue and thewhole was extracted with methylene chloride. The extract was purified bysilica gel column chromatography. The resulting white solid wasrecrystallized from hexane to obtain 0.10 g of4-cyano-4'(6-hydroxyhexyloxy)biphenyl (9) (yield: 66.4%).

¹ H-NMR δ (CDCl₃, ppm); 1.10-2.10 (m, 8H), 3.67 (m, 2H), 4.00 (t, 2H,J═6.2Hz), 6.96 (d, 2H, J═8.8Hz), 7.50 (d, 2H, J═8.8Hz), 7.65 (s, 4H).

IR (KBr, cm⁻¹); 3350 (--OH), 2945, 2860, 2220 (--CN), 1600, 1580, 1495,1470, 1290, 1250, 1180, 1020, 1010, 820.

To a solution of 1.26 g (4.27 mmol) of the resulting compound (9) and1.8 ml (24.8 mmol) of anhydrous triethylamine dissolved in 20 ml oftetrahydrofuran under argon atmosphere was added dropwise 5 ml of antetrahydrofuran solution containing 0.38 ml (4.08 mmol) of acryloylchloride. The whole was stirred at room temperature overnight, thereby asalt precipitated. After addition of water to the reaction mixture, thewhole was extracted with diethyl ether. The extract was purified bysilica gel column chromatography. The resulting pale yellow solid wasrecrystallized from methanol to obtain 1.01 g of4-cyano-4'-(6-acryloxyhexyloxy)biphenyl (10) (yield: 67.7%).

¹ H-NMR, δ (CDCl₃, ppm); 1.10-2.10 (m, 8H), 4.01 (t, 2H, J═6.2Hz), 4.11(t, 2H, J═6.4Hz), 5.80 (dd, 1H, J═2.7, 9.7Hz), 6.10 (m, 1H), 6.40 (m,1H), 6.98 (d, 2H, J═8.8Hz), 7.52 (d, 2H, J═8.8Hz), 7.66 (s, 4H).

IR (KBr, cm⁻¹); 2945, 2860, 2220 (--CN), 1715 (C═O), 1600, 1495, 1470,1400, 1290, 1250, 1200, 1180, 1010, 1000, 820.

Reference Example 3

Synthesis of a monomer having a siloxane spacer ##STR15##

To a solution of 15.0 g (98.6 mmol) of methyl p-hydroxybenzoate and 13.0g (94.1 mmol) of potassium carbonate mixed in 150 ml of acetone wereadded 13 ml (150 mmol) of allyl bromide and the whole was stirred at 80°C. for 2 hours under an argon gas atmosphere. Water was added to thesolution and the whole was extracted with ethyl acetate. Then, theorganic phase was washed with 5% aqueous solution of sodium hydroxideand saturated saline solution. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 18.6 g of methyl p-allyloxybenzoate (11)(yield: 96.6%).

¹ H-NMR, δ (CDCl₃, ppm); 3.88 (s, 3H), 4.58 (d, 2H, J═5.0Hz), 5.37 (m,2H), 5.86-6.22 (m, 1H), 6.92 (d, 2H, J═9.0Hz), 7.98 (d, ² H, J═9.0Hz).

IR (KBr, cm⁻¹); 2960, 1720 (C═O), 1610, 1510, 1435, 1280, 1255, 1170,1110, 1020, 845, 770.

Mass (m/e); 192 (M⁺), 161, 41 (CH₂ ═CHCH₂ ⁺).

18.0 g (93.6 mmol) of the resulting compound (11) was dissolved in 600ml of ethanol. The solution was poured into a solution of 12.0 g (300mmol) of sodium hydroxide dissolved in 80 ml of water and 100 ml ofmethanol. The whole was refluxed at 80° C. for 2 hours. After removal ofthe solvent by distillation, the resulting white solid was dissolved inwater and the solution was rendered acidic by adding hydrochloric acid,whereby white precipitate formed. The precipitate was extracted withmethylene chloride. After removal of the solvent by distillation, theresidue was purified by silica gel column chromatography to obtain 4.7 gof p-allyloxybenzoic acid (12) (yield: 88.1%).

¹ H-NMR, δ (CDC₃, ppm); 4.56 (d, 2H, J═5.0Hz), 5.35 (m, 2H), 5.84-6.28(m, 1H), 6.90 (d, 2H, J═9.0Hz), 7.95 (d, 2H, J═9.0Hz).

IR (KBr, cm⁻¹); 2450-3000 (COOH), 1680 (C═O), 1600, 1550, 1430, 1350,1250, 1180, 1010, 1000, 930, 850, 770. Mass (m/e); 178 (M+), 41 (CH₂═CHCH₂ +).

30.0 g of PPE, 5.00 g (28.1 mmol) of the compound (12) and 4.40 g (28.9mmol) of p-butoxyphenol were dissolved in 100 ml of chloroform under anargon gas atmosphere and the whole was stirred at room temperatureovernight. After addition of water to the reaction mixture, the wholewas extracted with methylene chloride. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 8.30 g of p-butoxyphenyl p-allyloxybenzoate(13) (yield: 94.6%).

1H-NMR, δ (CDCl₃, ppm); 1.05 (t, 3H), 1.70-1.94 (m, 2H,), 3.93 (t, 2H,J═6.0Hz), 4.63 (d, 2H, J═5.0Hz), 5.39 (m, 2H), 5.88-6.13 (m, 1H),6.85-7.16 (m, 6H), 8.14 (d, 2H, J═8.9Hz).

IR (KBr, cm⁻¹); 2950, 1725 (C═O), 1605, 1515, 1480, 1460, 1430, 1320,1310, 1280, 1260, 1170, 1080, 1020, 940, 850, 800, 760.

Mass (m/e); 312 (M+), 279, 161, 41 (CH₂ ═CHCH₂ ⁺).

6.00 g (18.4 mmol) of the resulting compound (13) and 3.60 ml (45.9mmol) of dimethylethoxysilane were dissolved in 50 ml oftetrahydrofuran, and 0.10 ml of a methylene chloride solution (0.1mol/1) of dicyclopentadienylplatinum dichloride was added thereto. Thewhole was stirred at 50° C. overnight. Removal of the solvent bydistillation afforded p-butoxyphenyl p- (3-dimethylethoxysilylpropoxy)benzoate (14) as a crude product. Then, the product was again dissolvedin 20 ml of tetrahydrofuran and an aqueous solution containing 20.0 g(145 mmol) of potassium carbonate and 10 ml of acetone were addedthereto. The whole was stirred at room temperature for 4 days. Thereaction mixture was poured into an excess of ice-water containing 8.0 gof potassium dihydrogen phosphate and the whole was extracted withmethylene chloride. After removal of the solvent by distillation, theresidue was purified by silica gel column chromatography to obtain 2.68g of a silanol compound (15) (yield: 41.6% through two steps).

¹ H-NMR, δ (CDCl₃, ppm); 0.19 (s, 6H), 0.72-1.05 (m, 5H), 1.36-2.00 (m,6H), 3.90-4.12 (m, 4H), 6.86-7.16 (m, 6H), 8.13 (d, 2H, J═9.0Hz).

IR (KBr, cm⁻¹); 3250 (--OH), 2950, 1720 (C═O), 1600, 1500, 1260 (Si--C),1180, 1160, 1080, 840, 760, 700. Mass (m/e); 388 (M⁺), 237, 195, 121, 75(HOMe₂ Si⁺).

To a solution 1.50 g (3.86 mmol) of the resulting compound (15)dissolved in 10 ml of tetrahydrofuran under an argon gas atmosphere wereadded 0.65 ml (4.66 mmol) of triethylamine and 1.00 g (4.53 mmol) of3-methacryloxypropyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white solid formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 2.00 g of the desired monomer (16) (yield:90.5%).

¹ H-NMR, δ (CDCl₃, ppm); 0.11 (s, 12H), 0.48-0.57 (m, 4H), 0.98 (t, 3H,J═6.9Hz), 1.44-1.88 (m, 8H), 1.95 (s, 3H), 3.89-4.20 (m, 6H), 5.54 (s,1H), 6.11 (s, 1H), 6.85-7.14 (m, 6H), 8.14 (d, 2H).

IR (KBr, cm⁻¹); 2990, 2900, 1740 (C═O), 1650, 1615, 1520, 1260 (Si--C),1170, 1080, 1055(SiOSi), 850, 800. Mass (m/e); 572 (M⁺), 421, 279, 217,69 (CH₂ ═C(CH₃)CO⁺), 41 (CH₂ ═C (CH₃)⁺).

Reference Example 4

Synthesis of a monomer having a siloxane spacer ##STR16##

15.0 g of PPE, 4.00 g (22.4 mmol) of the compound (12) and 2.66 g (22.3mmol) of p-cyanophenol were dissolved in ml of chloroform under an argongas atmosphere and the whole was stirred at room temperature overnight.After addition of water to the reaction mixture, the whole was extractedwith methylene chloride. After removal of the solvent by distillation,the residue was purified by silica gel column chromatography to obtain4.80 g of p-cyanophenyl p-allyloxybenzoate (17) as a white solid (yield:76.7%).

¹ H-NMR, δ (CDCl₃, ppm); 4.63 (d, 2H, J═5.0Hz), 5.39 (m, 2H),5.88-6.24(m, 1H), 7.01 (d, 2H, J═8.8Hz), 7.34 (d, 2H, J═8.8Hz), 7.73 (d,2H, J═8.8Hz), 8.13 (d, 2H, J═8.8Hz). IR (KBr, cm⁻¹); 2960, 2230 (--CN),1720 (C═O), 1600, 1580, 1500, 1450, 1420, 1325, 1310, 1260, 1200, 1180,1060, 990, 920, 880, 840, 755.

Mass spectrum (m/e); 279 (M⁺), 161, 41 (CH₂ ═CHCH₂ ⁺).

1.90 g (5.72 mmol) of the resulting compound (17) and 2.50 ml (18.2mmol) of dimethylethoxysilane were dissolved in 30 ml of tetrahydrofuranand 0.20 ml of a methylene chloride solution (0.1 mol/1) ofdicyclopentadienylplatinum dichloride was added thereto. The whole wasstirred at 50° C. for 3 hours under an argon gas atmosphere. Afterremoval of the solvent by distillation, the residue was purified bysilica gel column chromatography to obtain 1.80 g of p-cyanophenylp-(3-dimethylethoxysilylpropoxy)benzoate (18) as a colorless clearliquid (yield: 72.9%).

¹ H-NMR, δ (CDCl₃, ppm); 0.14 (s, 6H), 0.63-0.82 (m, 2H), 1.19 (t, 3H),1.60-1.98 (m, 2H), 3.68 (q, 2H), 4.03 (t, 2H), 6.97 (d, 2H, J═8.8Hz),7.34 (d, 2H, J═8.8Hz), 7.72 (d, 2H, J═8.8Hz), 8.12 (d, 2H, J═8.8Hz).

IR (KBr, cm⁻¹); 3000, 2960, 2890, 2200 (--CN), 1730 (C═O), 1600, 1580,1510, 1475, 1420, 1410, 1390, 1260 (Si--C), 1200, 1150, 1040, 990, 940,880, 840, 800, 770, 750.

Mass (m/e); 368 (M⁺ --Me), 326, 265, 145, 121, 103 (EtOMe₂ Si⁺).

A solution of 1.75 g of the product (18) dissolved in 35 ml of acetonewas poured into a solution of 1.5 g (10.9 mmol) of potassium carbonatedissolved in 25 ml of water and 60 ml of acetone. Then, an aqueoussolution of 1.5 g (10.9 mmol) of potassium carbonate dissolved in 45 mlof water was added thereto. The whole was stirred at room temperaturefor 2 hours. The reaction mixture was poured into an excess of ice-watercontaining 5.0 g of potassium dihydrogen phosphate and the whole wasextracted with methylene chloride. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 1.40 g of a silanol compound (19) as a whitesolid (yield: 86.4%).

¹ H-NMR, δ (CDCl₃, ppm); 0.19 (s, 6H), 0.67-0.89 (m, 2H), 1.70 (s, 1H),1.83-2.02 (m, 2H), 3.67 (t, 2H, J═6.1Hz), 6.98 (d, 2H, J═8.9Hz), 7.35(d, 2H, J═8.8Hz), 7.73 (d, 2H, J═8.9Hz), 8.12 (d, 2H, J═8.8Hz). IR (KBr,cm⁻¹); 3500 (--OH), 2950, 2880, 2240 (--CN), 1930, 1720 (C═O), 1600,1510, 1470, 1410, 1390, 1320, 1250 (Si--C), 1200, 1150, 1040, 1000, 870,820, 760.

Mass (m/e); 355 (M⁺), 340 (M⁺ -Me), 237, 195, 121, 75 (HOMe₂ Si⁺).

To a solution of 1.25 g (3.52 mmol) of the resulting compound (19)dissolved in 15 ml of tetrahydrofuran under an argon gas atmosphere wereadded 1.00 ml (7.17 mmol) of triethylamine and 0.93 g (4.22 mmol) of3-methacryloxypropyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white salt formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 1.72 g of the desired monomer (20) as a whitesolid (yield: 90.5%).

¹ H-NMR, δ (CDCl₃, ppm); 0.10 (s, 12H), 0.53-0.75 (m, 4H), 1.61-1.96 (m,4H), 1.94 (s, 3H), 4.03 (t, 2H, J═6.0Hz), 4.31 (t, 2H, J═6.2Hz), 5.53(s, 1H), 6.10 (s, 1H), 6.98 (d, 2H, J═8.8Hz), 7.35 (d, 2H, J═8.9Hz),7.73 (d, 2H, J═8.8Hz), 8.12 (d, 2H, J═8.9Hz).

IR (KBr, cm⁻¹); 2950, 2900, 2250 (--CN), 1740 (C═O), 1720, 1600, 1510,1320, 1300, 1255 (Si--C), 1210, 1160, 1060 (SiOSi) , 1000, 840, 800.

Mass (m/e); 524 (M⁺ --Me), 482, 440, 421, 217, 121, 69 (CH₂ ═C (CH₃)COO⁺), 41 (CH₂ ═C (CH₃)⁺).

Reference Example 5

Synthesis of a monomer having a siloxane spacer ##STR17##

20.0 g of PPE, 4.86 g (27.3 mmol) of the compound (12) and 6.60 g (27.3mmol) of 4-butoxy-4'-hydroxybiphenyl were dissolved in 100 ml ofchloroform under an argon gas atmosphere and the whole was stirred atroom temperature overnight. After addition of water to the reactionmixture, the whole was extracted with methylene chloride. After removalof the solvent by distillation, the residue was purified by silica gelcolumn chromatography to obtain 9.15 g of 4-(4'-butoxybiphenyl)p-allyloxybenzoate (21) as a white solid (yield: 83.4%).

¹ H-NMR δ (CDCl₃, ppm); 0 98 (t, 3H, J═6 3Hz), 1.38-1.89 (m, 4H), 4.01(t, 2H, J═6.0Hz), 4.64 (d, 2H, J═5.0Hz), 5.45 (m, 2H), 5.94-6.13 (m,1H), 6.96 (d, 2H, J═8.8Hz), 7.00 (d, 2H, J═8.8Hz), 7.24 (d, 2H,J═8.8Hz), 7.50 (d, 2H, J═8.9Hz), 7.58 (d, 2H, J═8.8Hz), 8.16 (d, 2H,J═8.9Hz).

IR (KBr, cm⁻¹); 2960, 2940, 2880, 1720 (C═O), 1600, 1510, 1470, 1320,1245, 1210, 1160, 1070, 1040, 940, 840, 810, 760.

Mass (m/e); 402 (M⁺), 161, 41 (CH₂ ═CHCH₂ ⁺).

8.75 g (21.0 mmol) of the resulting compound (21) and 7.30 ml (53.0mmol) of dimethylethoxysilane were dissolved in 100 ml oftetrahydrofuran and 0.50 ml of a methylene chloride solution (0.1 mol/1)of dicyclopentadienylplainum dichloride was added thereto. The whole wasstirred at 50° C. for 3 hours under an argon gas atmosphere. Removal ofthe solvent by distillation afforded 4-(4'-butoxybiphenyl)p-(3-dimethylethoxysilylpropoxy)benzoate (22) as a crude product. Then,the product was dissolved in 35 ml of acetone and 50 ml oftetrahydrofuran and the solution was poured into a solution of 9.0 g(65.1 mmol) of potassium carbonate dissolved in 15 ml of water and 45 mlof acetone. Further, a solution of 9.0 g (65.1 mmol) of potassiumcarbonate dissolved in 45 ml of water was added thereto. The whole wasstirred at room temperature for 8 hours. The reaction mixture was pouredinto an excess of ice-water containing 30 g of potassium dihydrogenphosphate and the whole was extracted with methylene chloride. Afterremoval of the solvent by distillation, the residue was purified bysilica gel column chromatography to obtain 4.38 g of a silanol compound(23) as a white solid (yield: 42.2% through two steps).

¹ H-NMR, δ (CDCl₃, ppm); 0.12 (s, 6H), 0.52-0.82 (m, 2H), 0.98 (t, 3H,J═6.5Hz), 1.12-1.92 (m, 7H), 3.97 (t, 2H, J═7.0Hz), 4.00 (t, 2H,J═7.1Hz), 6.92 (d, 4H, J═8.8Hz), 7.20 (d, 2H, 8.9Hz), 7.84 (d, 2H,J═8.8Hz), 7.92 (d, 2H, J═8.9Hz), 8.10 (d, 2H, J═8.8Hz).

IR (KBr, cm⁻¹); 3400 (--OH), 2960, 2940, 2880, 1740 (C═O), 1720, 1620,1510, 1490, 1440, 1410, 1260 (Si--C), 1220, 1175, 1090, 1060, 1010, 990,900, 840, 820, 780.

Mass (m/e); 478 (M⁺), 416, 362, 242, 186, 121, 75 (HOMe₂ Si⁺).

To a solution 3.90 g (8.15 mmol) of the resulting compound (23)dissolved in 30 ml of tetrahydrofuran under an argon gas atmosphere wereadded 3.27 ml (23.7 mmol) of triethylamine and 2.10 g (9.46 mmol) of3-methacryloxypropyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white salt formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 3.00 g of the desired monomer (24) as a whitesolid (yield: 55.5%).

¹ H-NMR, δ (CDCl₃, ppm); 0.10 (s, 12H), 0.54-0.86 (m, 4H), 1.00 (t, 3H,J═6.5Hz), 1.20-1.90 (m, 4H), 1.94 (d, 3H, J═5.0Hz), 4.02 (t, 4H,J═7.1Hz), 4.11 (t, 2H, J═7.1Hz), 5.54 (s, 1H), 6.10 (s, 1H), 6.97 (d,4H, J═8.8Hz), 7.27 (d, 2H, J═8.8Hz), 7.51 (d, 2H, J═8.8Hz), 7.58 (d, 2H,J═8.9Hz), 8.16 (d, 2H, J═8.9Hz).

IR (KBr, cm⁻¹); 2960, 2940, 2880, 1730 (C═O), 1605, 1500, 1470, 1320,1290, 1250 (Si--C), 1215, 1170, 1070 (SiOSi), 1040, 1010, 970, 900, 840,810.

Mass (m/e); 662 (M⁺), 493, 421, 379, 337, 242, 217, 121, 69 (CH₂ ═C(CH₃) COO⁺), 41 (CH₂ ═C (CH₃)⁺).

Reference Example 6

Synthesis of a monomer having a siloxane spacer ##STR18##

15.0 g of PPE, 2.65 g (15.2 mmol) of the compound (12) and 4.50 g (13.4mmol) of 4-octyloxy-4'-hydroxybiphenyl were dissolved in 120 ml ofchloroform under an argon gas atmosphere and the whole was stirred atroom temperature overnight. After addition of water to the reactionmixture, the whole was extracted with methylene chloride. After removalof the solvent by distillation, the residue was purified by silica gelcolumn chromatography to obtain 5.30 g of 4- (4'-octyloxybiphenylp-allyloxybenzoate (25) as a white solid (yield: 86.2%).

¹ H-NMR, δ (CDCl₃, ppm); 0.73 (t, 3H, J═6.9H), 1.00-1.85 (m, 12H), 3.96(t, 2H, J═6.4Hz), 4.60 (d, 2H, J═5.1Hz), 5.39 (m, 2H), 5.85-6.23 (m,1H), 6.93 (d, 2H, J═8.8 Hz), 6.97 (d, 2H, J═9.0Hz), 7.20 (d, 2H, J═8.8Hz), 7.47 (d, 2H, J═8.8 Hz), 7.55 (d, 2H, J═8.8 Hz), 8.13 (d, 2H,J═9.0Hz).

IR (KBr, cm⁻¹); 2960, 2930, 2850, 1725 (C═O), 1610, 1500, 1470, 1310,1290, 1250, 1215, 1165, 1080, 1010, 995, 930, 880, 840, 800, 760, 690.

Mass (m/e); 458 (M⁺), 298, 161, 41 (CH₂ ═CHCH₂ ⁺).

5.00 g (10.9 mmol) of the resulting compound (25) and 2.5 ml (18.2 mmol)of dimethylethoxysilane were dissolved in 50 ml of tetrahydrofuran and0.20 ml of a methylene chloride solution (0.1 mol/1) ofdicyclopentadienylplatinum dichloride was added thereto. The whole wasstirred at 50° C. for 3 hours under an argon gas atmosphere. Removal ofthe solvent by distillation afforded 4-(4'-octyloxybiphenyl)p-(3-dimethylethoxysilylpropoxy) benzoate (26) as a crude product. Then,the product was dissolved in 40 ml of acetone and 60 ml oftetrahydrofuran, and the solution was poured into a solution of 3.5 g(25.3 mmol) of potassium carbonate dissolved in 50 ml of water and 120ml of tetrahydrofuran. Further, a solution of 3.5 g (25.3 mmol) ofpotassium carbonate dissolved in 100 ml of water was added thereto. Thewhole was stirred at room temperature for 2 hours. The reaction mixturewas poured into an excess of ice-water containing 12 g of potassiumdihydrogen phosphate and the whole was extracted with methylenechloride. After removal of the solvent by distillation, the residue waspurified by silica gel column chromatography to obtain 4.01 g of asilanol compound (27) as a white solid (yield: 68.8% through two steps).

¹ H-NMR, δ (CDCl₃, ppm); 0.20 (s, 6H), 0.58-0.70 (m, 2H), 0.75 (t, 3H,J═6.4Hz), 1.20-2.10 (m, 15H), 4.01 (t, 2H, J═6.4Hz), 4.06 (t, 2H,J═6.7Hz), 6.98 (d, 4H, J═8.8Hz), 7.25 (d, 2H, J═9.0Hz), 7.52 (d, 2H,J═8.8Hz), 7.59 (d, 2H, J═8.8Hz), 8.17 (d, 2H, J═9.0Hz).

IR (KBr, cm⁻¹); 3280 (--OH), 2960, 2940, 2860, 1740 (C═O), 1610, 1510,1500, 1470, 1400, 1250 (Si--C), 1220, 1160, 1075, 1040, 1000, 890, 840,800, 760, 680.

Mass (m/e); 534 (M⁺), 418, 298, 237, 195, 121, 75 (HOMe₂ Si⁺).

To a solution 3.60 g (6.73 mmol) of the compound (27) dissolved in 25 mlof tetrahydrofuran under an argon gas atmosphere were added 2.00 ml(14.3 mmol) of triethylamine and 1.48 g (6.71 mmol) of3-methacryloxypropyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white salt formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 2.01 g of the desired monomer (28) as a whitesolid (yield: 38.2%).

¹ H-NMR, δ (CDCl₃, ppm); 0.11 (s, 12H), 0.32-0.65 (m, 4H), 0.75 (t, 3H,J═6.4Hz), 1.10-1.90 (m, 16H), 1.95 (s, 3H), 4.00-4.15 (m, 6H), 5.54 (s,1H), 6.11 (s, 1H), 6.97 (d, 4H, J═8.8Hz), 7.24 (d, 2H, J═9.0Hz), 7.51(d, 2H, J═8.8Hz), 7.59 (d, 2H, J═8.8Hz), 8.16 (d, 2H, J═9.0Hz).

IR (KBr, cm⁻¹); 3000, 2950, 2900, 1730 (C═O), 1610, 1510, 1500, 1260(Si--C), 1210, 1170, 1070, 1070 (SiOSi), 900, 840, 820, 770.

Mass (m/e); 719 (M⁺) 549 421 379 298 217 121 69 (CH₂ ═C (CH₃) COO³⁰), 41(CH₂ ═C (CH₃)⁺)

Reference Example 7

Synthesis of a monomer having a siloxane spacer ##STR19##

To a solution of 33.0 g (196 mmol) of methyl 2,4-dihydroxybenzoate and68.0 g (491 mmol) of potassium carbonate mixed in 500 ml of 2-butanonewas added 50 ml (235 mmol) of octyl bromide and the whole was refluxedfor 18 hours. Water was added to the solution and the whole wasextracted with ethyl acetate. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 40.4 g of methyl 2-hydroxy-4-octyloxybenzoate(29) as a colorless clear liquid (yield: 73.5%).

¹ H-NMR, δ(CDCl₃, ppm); 0.81-0.94 (m, 3H), 1.18-1.98 (m, 12H), 3.90 (s,3H), 3.97 (t, 2H, J═6.0Hz), 6.35-6.49 (m, 2H), 7.66-7.77 (m, 1H).

IR (KBr, cm⁻¹); 3080 (--OH), 2930, 2860, 1730(C═O), 1700, 1605, 1570,1505, 1470, 1440, 1380, 1270, 1190, 1140, 1090, 1030, 920, 830, 770.

To a solution of 22.0 g (78.5 mmol) of the compound (29) and 65.0 g (471retool) of potassium carbonate mixed in 300 ml of 2-butanone were added32.0 g (236 mmol) of butenyl bromide and the whole was refluxed for 18hours. Water was added to the solution and the whole was extracted withethyl acetate. After removal of the solvent by distillation, the residuewas purified by silica gel column chromatography to obtain 23.6 g ofmethyl 2-butenyloxy-4-octyloxybenzoate as a colorless clear liquid(yield: 89.9%). Then, 20.0 g (59.8 mmol) of the resulting compound wasdissolved in 100 ml of methanol. The solution was poured into a solutionof 12.0 g (300 mmol) of sodium hydroxide dissolved in 40 ml of water and400 ml of methanol. The whole was refluxed for another 2 hours. Afterremoval of the solvent by distillation, the resulting white solid wasdissolved in water and the solution was rendered acidic by addinghydrochloric acid, whereby white precipitate formed. The precipitate wasextracted with methylene chloride. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 15.3 g of 2-butenyloxy-4-octyloxybenzoic acid(30) (yield: 80.0%).

¹ H-NMR, δ (CDCl₃, ppm); 0.80-0.96 (m, 3H), 1.23-1.68 (m, 12H), 2.69 (q,2H, J═6.3Hz), 4.01 (t, 2H, J═6.3Hz), 4.26 (t, 2H, J═6.3Hz), 5.14-5.35(m, 2H), 5.73-5.84 (m, 1H), 6.49-6.68 (m, 2H), 8.11 (d, 1H, J═8.8Hz).

IR (KBr, cm⁻¹ ); 3400 (--OH), 2920, 2860, 1730(C═O), 1610, 1580, 1510,1490, 1450, 1360, 1260, 1200, 1180, 1070, 1030, 945, 880, 830, 780.

20.0 g of PPE, 4.00 g (28.1 mmol) of the compound (30) and 3.00 g (12.5mmol) of 4-butoxy-4'-hydroxybiphenyl were dissolved in 80 ml ofchloroform under an argon gas atmosphere and the whole was stirred at60° C. for 3 days. After addition of water to the reaction mixture, thewhole was extracted with methylene chloride. After removal of thesolvent by distillation, the residue was purified by silica gel columnchromatography to obtain 6.28 g of 4-(4'-butoxybiphenyl)2-(3-butenyloxy)-4-octyloxybenzoate (31) (yield: 91.4%).

¹ H-NMR, δ (CDCl₃, ppm); 0.80-1.09 (m, 6H), 1.09-1.53 (m, 16H), 2.61 (q,2H, J═6.6Hz), 3.85 (s, 2H), 4.06 (t, 4H, J═6.7Hz), 5.01-5.24 (m, 2H),5.78-6.14 (m, 1H), 6.50-6.61 (m, 2H), 6.97 (d, 2H, J═8.8Hz), 7.23 (d,2H, J═8.6Hz), 7.47-7.61 (m, 4H), 8.03 (d, 1H, J═9.2Hz).

IR (KBr, cm⁻¹); 2930, 2860, 1740 (C═O), 1610, 1570, 1500, 1470, 1430,1390, 1330, 1270, 1250, 1210, 1170, 1150, 1070, 1040, 1000, 910, 875,830, 800, 760.

Mass (m/e); 544 (M⁺), 303, 185, 137, 55 (CH₂ ═CHCH₂ ⁺).

4.10 g (7.60 mmol) of the resulting compound (31) and 1.20 ml (9.12mmol) of dimethylethoxysilane were dissolved in 50 ml of tetrahydrofuranand 0.10 ml of a methylene chloride solution (0.1 mol/1) ofdicyclopentadienylplatinum dichloride was added thereto. The whole wasstirred at 60° C. overnight. Removal of the solvent by distillationafforded an ethoxysilyl compound (32) as a crude product. Then, theproduct was again dissolved in 20 ml of tetrahydrofuran, and an aqueoussolution containing 5.20 g (30.4 mmol) of potassium carbonate and 10 mlof acetone were added thereto. The whole was stirred at room temperaturefor 3 days. The reaction mixture was poured into an excess of ice-watercontaining 8.0 g of potassium dihydrogen phosphate and the whole wasextracted with methylene chloride. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 1.68 g of a silanol compound (33) (yield: 35.7%through two steps).

¹ H-NMR, 5 (CDCl₃, ppm); 0.11 (s, 6H), 0.50-0.72 (m, 2H), 0.89-0.96 (m,6H), 1.24-2.15 (m, 20H), 3.95-4.05 (m, 6H), 6.50-6.60 (m, 2H), 6.98 (d,2H, J═8.8Hz), 7.24 (d, 2H, J═8.6Hz), 7.45-7.60 (m, 4H), 8.04 (d, 1H,J═9.2Hz).

IR (KBr, cm⁻¹); 3380 (--OH), 2930, 2860, 1745 (C═O), 1610, 1570, 1500,1470, 1435, 1390, 1250 (Si--C), 1210, 1170, 1150, 1035, 1000, 970, 880,830, 800, 760.

To a solution 1.10 g (1.78 mmol) of the resulting compound (33)dissolved in 25 ml of tetrahydrofuran under an argon gas atmosphere wereadded 0.50 ml (3.60 mmol) of triethylamine and 0.50 g (2.16 mmol) of3-methacryloxypropyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white salt formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 0.75 g of the desired monomer (34) (yield:51.4%).

¹ H-NMR, 5 (CDCl₃, ppm); 0.02 (s, 6H), 0.05 (s, 6H), 0.45-0.65 (m, 4H),0.85-1.93 (m, 22H), 1.95 (s, 3H), 3.95-4.15 (m, 8H), 5.54 (s, 1H), 6.10(s, 1H), 6.50-6.60 (m, 2H), 6.98 (d, 2H, J═8.8Hz), 7.24 (d, 2H,J═8.6Hz), 7.45-7.60 (m, 4H), 8.04 (d, 1H, J═9.2Hz).

IR (KBr, cm⁻¹); 2930, 2870, 1745 (C═O), 1720, 1610, 1570, 1500, 1499,1435, 1390, 1300, 1250 (Si--C), 1205, 1170, 1045, 1000, 970, 880, 800,760.

Mass (m/e); 804 (M⁺ -Me), 677, 637, 565, 563, 242, 217, 186, 137, 69(CH₂ ═C (CH₃) CO⁺), 41 (CH₂ ═C (CH₃) +).

Reference Example 8

Synthesis of a monomer having a siloxane spacer ##STR20##

23.0 g of PPE, 5.00 g (15.6 mmol) of the compound (30) and 3.10 g (15.6mmol) of 4-cyano-4'-hydroxybiphenyl were dissolved in 200 ml ofchloroform under an argon gas atmosphere and the whole was stirred at60° C. for 3 days. After addition of water to the reaction mixture, thewhole was extracted with methylene chloride. After removal of thesolvent by distillation, the residue was purified by silica gel columnchromatography to obtain 7.00 g of 4-(4'-cyanobiphenyl)2-(3-butenyloxy)-4-octyloxybenzoate (35) (yield: 93.6%).

¹ H-NMR, 8 (CDCl₃, ppm); 0.80-1.03 (m, 6H), 1.03-1.93 (m, 12H), 2.69 (q,2H, J═6.5Hz), 4.06 (t, 2H, J═6.5Hz), 4.14 (t, 2H, J═6.3Hz), 5.17-5.30(m, 2H), 5.80-6.17 (m, 1H), 6.54-6.66 (m, 2H), 7.33 (d, 2H, J═8.6Hz),7.65 (m, 2H, J═8.9Hz), 7.72 (s, 4H), 8.07 (d, 1H, J═8.8Hz).

IR (KBr, cm⁻¹); 2930, 2850, 2220 (--CN), 1740 (C═O), 1605, 1570, 1490,1460, 1435, 1390, 1310, 1220, 1200, 1140, 1030, 1000, 920, 835, 800,760.

4.00 g (8.34 mmol) of the resulting compound (35) and 2.90 ml (20.8mmol) of dimethylethoxysilane were dissolved in 30 ml of tetrahydrofuranand 0.10 ml of a methylene chloride solution (0.1 mol/1) ofdicyclopentadienylplatinum dichloride was added thereto. The whole wasstirred at 60° C. overnight. Removal of the solvent by distillationafforded an ethoxysilyl compound (36) as a crude product. Then, theproduct was again dissolved in 20 ml of tetrahydrofuran, and an aqueoussolution containing 1.20 g (33.4 mmol) of potassium carbonate and 10 mlof acetone were added thereto. The whole was stirred at room temperaturefor 3 days. The reaction mixture was poured into an excess of ice-watercontaining 8.0 g of potassium dihydrogen phosphate and the whole wasextracted with methylene chloride. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 2.10 g of a silanol compound (37) (yield: 44.0%through two steps).

1H-NMR, δ (CDCl₃, ppm); 0.11 (s, 6H), 0.48-0.72 (m, 2H), 0.90-0.96 (m,3H), 1.24-2.17 (m, 16H), 3.96-4.04 (m, 4H), 6.50-6.58 (m, 2H), 7.31 (d,2H, J═8.4Hz), 7.62 (d, 2H, J═8.8Hz), 7.72 (s, 4H), 8.04 (d, 1H,J═9.2Hz).

IR (KBr, cm⁻¹); 3400 (--OH), 2930, 2230 (--CN), 1720 (C═O), 1570, 1490,1470, 1435, 1390, 1250 (Si-C), 1200, 1170, 1030, 1000, 840.

To a solution of 1.90 g (3.32 mmol) of the resulting compound (37)dissolved in 50 ml of tetrahydrofuran under an argon gas atmosphere wereadded 0.95 ml (6.84 mmol) of triethylamine and 0.91 g (4.10 mmol) of3-methacryloxy-propyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white salt formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 1.33 g of the desired monomer (38) (yield:52.8%).

¹ H-NMR, δ (CDCl₃, ppm); 0.02 (s, 6H), 0.05 (s, 6H), 0.43-0.65 (m, 4H),0.85-1.84 (m, 18H), 1.94 (s, 3H), 3.97-4.16 (m, 6H), 5.54 (s, 1H), 6.10(s, 1H), 6.51-6.59 (m, 2H), 7.31 (d, 2H, J═8.8Hz), 7.62 (d, 2H,J═8.8Hz), 7.72 (s, 4H), 8.04 (d, 1H, J═9.2Hz ).

IR (KBr, cm⁻¹); 2930, 2860, 2230 (═CN), 1720 (C═O), 1610, 1570, 1490,1470, 1435, 1390, 1300, 1250 (Si--C), 1200, 1170, 1040, 1000, 940, 840,740.

Reference Example 9

Synthesis of a monomer having a siloxane spacer ##STR21##

7.85 g (29.8 mmol) of (5R) -3- (4-hydroxyphenyl) -5-hexyl-2-oxazolidoneprepared according to the method described in a reference (JapanesePatent Application Laied-open No. 151371/1991), 32.0 g of PPE and 5.32 g(29.9 mmol) of the compound (12) were dissolved in 120 ml of chloroformunder an argon gas atmosphere and the whole was stirred at roomtemperature overnight. After addition of water to the reaction mixture,the whole was extracted with methylene chloride. After removal of thesolvent by distillation, the residue was purified by silica gel columnchromatography to obtain 10.2 g of4-((5R)-3-(5-hexyl-2-oxazolidonyl)phenyl) 4-allyloxybenzoate (39) as awhite solid (yield: 80.8%).

¹ H-NMR, δ (CDCl₃, ppm); 0.80-1.10 (m, 3H), 1.12-2.05 (m, 10H), 3.58(dd, 1H, J═8.6, 7.2Hz), 4.02 (d, 1H, J═8.5Hz), 4.56 (dt, 2H, J═1.3,4.9Hz), 4.51-4.92 (m, 1H), 5.31-5.58 (m, 2H), 5.71-6.44 (m, 1H), 6.92(d, 2H, J═9.0Hz), 7.13 (d, 2H, J═9.2Hz), 7.52 (d, 2H, J═9.0Hz), 8.07 (d,2H, J═9.0Hz). IR (KBr, cm⁻¹); 2950, 2900, 2850, 1720 (C═O), 1600, 1520,1460, 1430, 1410, 1280, 1250, 1220, 1170, 1140, 1120, 1080, 1010, 980,910, 870, 840, 750, 680, 520.

Mass (m/e); 423 (M⁺), 218, 161, 41 (CH₂ ═CHCH₂ ⁺). [α]_(D) ²⁰ ═13.4(c═1.29, CHCl₁).

8.30 g (19.5 mmol) of the resulting compound (39) and 5.0 ml (36.5 mmol)of dimethylethoxysilane were dissolved in 100 ml of tetrahydrofuran, and1 mg of dicyclopentadienyl-platinum dichloride was added thereto. Thewhole was stirred at 50° C. overnight. Removal of the solvent bydistillation afforded an ethoxysilyl compound (40) as a crude product.Then, the product was dissolved in 40 ml of acetone and 60 ml oftetrahydrofuran, and a solution of 5.0 g (36.0 mmol) of potassiumcarbonate dissolved in 50 ml of water and 120 ml of tetrahydrofuran wasadded thereto. The whole was stirred at room temperature overnight. Thereaction mixture was poured into an excess of ice-water containing 8.0 gof potassium dihydrogen phosphate and the whole was extracted withmethylene chloride. After removal of the solvent by distillation, theresidue was purified by silica gel column chromatography to obtain 4.00g of a silanol compound (41) as a white olid (yield: 41.1% through twosteps).

¹ H-NMR, δ (CDCl₃, ppm); 0.15 (s, 6H), 0.50-2.22 (m, 17H), 3.66 (dd, 1H,J═8.6, 7.2Hz), 4.04 (t, 1H, J═6.4Hz), 4.09 (t, 2H, J═8.5Hz), 4.50-4.80(m, 1H), 6.97 (d, 2H, J═9.0Hz), 7.21 (d, 2H, J═9.2Hz), 7.59 (d, 2H,J═9.0Hz), 8.13 (d, 2H, J═8.8Hz).

IR (KBr, cm⁻¹); 3000-3600 (--OH), 2950, 2930, 2850, 1740, 1720, 1600,1515, 1400, 1280, 1260 (Si--C), 1210, 1140, 1080, 870, 840, 760.

Mass (m/e); 499 (M⁺), 263, 237, 195, 121, 75 (HOMe₂ Si⁺). [α]_(D) ²⁰═8.4 (C═1.54, CHCl₃).

To a solution 3.80 g (7.60 mmol) of the resulting compound (41)dissolved in 80 ml of tetrahydrofuran under an argon gas atmosphere wereadded 1.70 ml (23.5 mmol) of triethylamine and 1.70 g (7.71 mmol) of3-methacryloxypropyldimethylchlorosilane and the whole was stirred atroom temperature overnight. A white salt formed was filtrated off underwashing with diethyl ether. After removal of the solvent bydistillation, the residue was purified by silica gel columnchromatography to obtain 1.20 g of the desired monomer (42) as a whitesolid (yield: 31.2%).

1H-NMR, δ (CDCl₃, ppm); 0.10 (s, 6H), 0.12 (s, 6H), 0.30-2.00 (m, 21H),1.95 (s, 3H), 3.65 (dd, 1H, J═7.5, 8.5Hz), 4.02 (t, 2H, J═6.8Hz), 4.11(t, 2H, J═6.9Hz), 3.91-4.18 (m, 1H), 5.54 (t, 1H, J═1.6Hz), 6.10 (s,1H), 6.97 (d, 2H, J═8.8Hz), 7.21 (d, 2H, J═9.0Hz), 7.60 (d, 2H,J═9.0Hz), 8.13 (d, 2H, J═8.8Hz).

IR (KBr, cm⁻¹); 2950, 2930, 2850, 1740 (C═O), 1720, 1600, 1500, 1400,1320, 1290, 1250, 1200, 1160, 1000-1100 (SiOSi), 980, 840, 800, 760.

Mass (m/e); 683 (M⁺), 668 (M⁺ -Me), 421, 217, 121, 69 (CH₂ ═C (CH₃)COO⁺).

[α]_(D) ²⁰ ═+27.2 (C═1.12, CHCl₃).

Working Examples 1˜12

Synthesis of copolymers and physical properties thereof ##STR22##[Copolymer](R═H or CH₃, k═6 or 11, p═3 or 4

Each of the monomers (4)˜(8) and (10) having alkylene spacers obtainedin Reference Examples 1 and 2 was mixed with each of the monomers havingsiloxane spacers obtained in Reference Example 3˜9 in a ratio cited inTable 1, and the mixture was dissolved in tetrahydrofuran so that theconcentration of the total monomers was to be 0.5 mol/l. Further,azobisisobutyronitrile was added so that the concentration was to be 25mmol/l. After the solution was conducted at 60° C. for 24 hours. Thereaction mixture was poured into excess of methanol. The resultingprecipitate was recovered and dissolved in tetrahydrofuran, andreprecipitated from methanol. The reprecipitation was repeated. Withrespect to the obtained copolymers, ¹ H-NMR analyses were conducted todetermine the compositions of copolymerization (x/y), and the numberaverage molecular weights and the weight average molecular weights weredetermined by calculation using polystyrene standard on gel permeationchromatography. In addition, the liquid crystallinity and phasetransition temperatures were determined on DSC measurements, X-raydiffraction, and polarization microscopic analyses. Table 1 shows thesummary of the results. As is apparent from the table, every copolymerexhibits nematic or smectic liquid crystalline phase at a relatively lowtemperature such as around room temperature.

                                      TABLE 1                                     __________________________________________________________________________               Molar ratio        Phase                                           Sample                                                                            Monomers                                                                             monomer-1/ Mn.sup.a)                                                                         Mw.sup.a)                                                                         transition                                      No. -1  -2 monomer-2                                                                            x/y ×10.sup.-4                                                                  ×10.sup.-4                                                                  temp. (°C.)                              __________________________________________________________________________    CP-1                                                                              (4) (16)                                                                             75/25  72/28                                                                             3.99                                                                              6.48                                                                              g 37 S 101 I                                    CP-2                                                                              (4) (16)                                                                             50/50  47/53                                                                             3.57                                                                              5.45                                                                              g 12 N 66 I                                     CP-3                                                                              (4) (34)                                                                             75/25  75/25                                                                             6.57                                                                              9.73                                                                              g 23 S 85 I                                     CP-4                                                                              (4) (34)                                                                             50/50  62/38                                                                             2.70                                                                              3.91                                                                              g 13 N 49 I                                     CP-5                                                                              (5) (20)                                                                             75/25  78/22                                                                             1.97                                                                              2.86                                                                              g 31 S 99 I                                     CP-6                                                                              (5) (20)                                                                             50/50  49/51                                                                             2.15                                                                              2.88                                                                              g 19 N 64 I                                     CP-7                                                                              (5) (38)                                                                             75/25  81/19                                                                             1.98                                                                              2.88                                                                              g 15 S 69 I                                     CP-8                                                                              (5) (38)                                                                             50/50  55/45                                                                             1.36                                                                              2.17                                                                              g 18 N 27 I                                     CP-9                                                                              (6) (24)                                                                             50/50  51/49                                                                             9.33                                                                              12.9                                                                              g 60 S 184 I                                    CP-10                                                                             (7) (28)                                                                             50/50  55/45                                                                             6.42                                                                              9.43                                                                              g 72 S 182 I                                    CP-11                                                                             (8) (42)                                                                             80/20  79/21                                                                             6.11                                                                              10.1                                                                              g 14 S* 40 S                                                                  105 N 114 I                                     CP-12                                                                             (10)                                                                              (20)                                                                             75/25  62/38                                                                             0.370                                                                             0.487                                                                             g -6 N 40 I                                     __________________________________________________________________________     .sup.a) Mn; the number average molecular weight                               Mw; the weight average molecular weight                                       .sup.b) g; glass state, S; smectic phase                                      S*; chiral smectic phase, N; nematic phase,                                   I; isotropic phase                                                       

The followings are ¹ H-NMR spectrum data of the obtained copolymers(δCDCl₃, ppm).

CP-1, CP-2:0.07 (s), 0.09 (s), 0.52 (bs), 0.65 (bs), 0.90-1.90 (m), 3.93(bt), 6.88 (m), 7.05 (d), 8.08 (bs).

CP-3, CP-4: 0.06 (s), 0.48 (bs), 0.55 (bs), 0.80-1.90 (m), 3.96 (b%),6.50 (bs), 6.90 (m), 7.06 (bs), 7.20 (bs), 7.47 (bs), 7.54 (bs), 8.01(bs), 8.09 (bs).

CP-5, CP-6: 0.08 (s), 0.52 (bs), 0.65 (bs), 0.80-1.90 (m), 3.92 (bs),4.00 (bs), 6.94 (bs), 7.32 (bs), 7.70 (bs), 8.10 (bs).

CP-7, CP-8:0.07 (s), 0.49 (bs), 0.55 (bs), 0.80-2.00 (m), 3.92 (m), 4.01(m), 6.52 (m), 6.95 (bs), 7.31 (m), 7.60 (bs), 7.70 (m), 8.03 (m), 8.10(bs).

CP-9: 0.07 (s), 0.55 (bs), 0.65 (bs), 0.80-1.90 (m), 3.95 (m), 6.91 (m),7.18 (m), 7.44 (bd), 7.50 (m), 8.10 (m).

CP-10: 0.07 (s), 0.54 (bs), 0.65 (bs), 0.90-1.90 (m), 3.95 (m), 6.91(m), 7.18 (m), 7.43 (m), 7.50 (m), 8.10 (m).

CP-11: 0.05 (s), 0.55 (bs), 0.64 (bs), 0.80-2.10 (m), 3.97 (m), 4.55(m), 6.92 (bs), 7.20 (m), 7.50 (m), 8.10 (bs).

CP-12: 0.07 (s), 0.52 (bs), 0.64 (bs), 1.3-2.1 (m), 3.97 (m), 6.95 (m),7.33 (m), 7.49 (m), 7.63 (m), 8.10 (m).

Reference Example 10

Synthesis of a monomer having a siloxane spacer ##STR23##

To a solution 1.48 g (8.15 mmol) of the compound (23) obtained inReference Example 5 dissolved in 100 ml of tetrahydrofuran under anargon gas atmosphere was added 0.43 ml (3.09 mmol) of triethylamine.30.0 ml (247 mmol) of dichlorodimethylsilane was placed in a 500 mlthree-necked flask and was cooled to 0° C. with ice bath. The abovesolution was slowly added dropwise through dropping funnel under anargon gas atmosphere thereto and the whole was further stirred at 0° C.for 1 hour. Then, the reaction flask was connected to a vacuum pump andexcess dichlorodimethylsilane and the solvent were removed under reducedpressure to render the intermediary product to be dryness. After theproduct was again dissolved into 30 ml of anhydrous tetrahydrofuran,0.75 g (3.71 mmol) of 3-methacryloxypropyldimethylsilanol was addedthereto and the whole was stirred at room temperature overnight. A whitesalt formed was filtrated off under washing with diethyl ether. Theproduct was purified by silica gel column chromatography to obtain 1.57g of the desired monomer (43) as a white solid (yield: 68.8%).

¹ H-NMR, δ (CDCl₃, ppm); 0.20 (s, 18H), 0.54-0.86 (m, 4H), 1.01 (t, 3H,J═6.2Hz), 1.20-2.22 (m, 8H), 2.25 (s, 3H), 4.36 (m, 6H), 6.08 (m, 1H),6.68 (m, 1H), 7.43 (d, 4H, J═7.9Hz), 7.70 (d, 2H, J═7.9Hz), 7.94 (d, 2H,J═8.6Hz), 8.05(d, 2H, J═8.6Hz), 8.60 (d, 2H, J═8.9Hz).

IR (KBr, cm⁻¹); 2970, 2940, 2900, 1730 (C═O), 1640, 1605, 1580, 1515,1500, 1475, 1420, 1320, 1290, 1260 (Si--C), 1220, 1170, 1110-1000(SiOSi), 970, 940, 900, 840, 800.

Mass (m/e); 736 (M⁺), 635, 561, 487, 439, 291, 217, 69 (CH₂ ═C (CH₃)CO⁺), 41 (CH₂ ═C (CH₃) ⁺).

Working Example 13

Synthesis of a copolymer and physical properties thereof ##STR24##

The monomer (4) obtained in Reference Example 1 and the monomer (43)obtained in Reference Example 10 were mixed in a ratio of 50/50, andwere copolymerized and purified according to the same method asdescribed in Examples 1˜12 to obtain a copolymer (CP-13). With respectto the obtained polymer, the composition of copolymerization (x/y) wasdetermined as 47/53 on 1H-NMR analysis, and the number average molecularweight and the weight average molecular weight were determined as2.42×10⁴ and 3.47×10⁴, respectively by calculation using polystyrenestandard on gel permeation chromatography. In addition, the liquidcrystallinity and phase transition temperature were measured on DSCmeasurements, X-ray diffraction, and polarization microscopic analyses.

phase transition temperature(°C.); g 29 S 93 N 146 I

¹ H-NMR, δ (CDCl₃, ppm); 0.08 (s), 0.14 (m), 0.56 (bs), 0.70 (m),0.80-1.90 (m), 3.94 (bs), 4.00 (m), 6.91 (bs), 6.97 (m), 7.08 (bs), 7.25(m), 7.50 (m), 8.10 (bs), 8.16 (m).

Comparative Example

Synthesis of homopolymers and physical properties thereof ##STR25##

Each of the monomers (4)˜(8) and (10) having alkylene spacers obtainedin Reference Examples 1 and 2 or each of the monomers having siloxanespacers obtained in Reference Examples 3˜10 was polymerized and purifiedaccording to the same method as described in Examples 1˜12 to obtain acorresponding homopolymer. With respect to the obtained polymers derivedfrom monomers having alkylene spacers, Table 2 shows the number averagemolecular weights and the weight average molecular weights determined bycalculation using polystyrene standard on gel permeation chromatography,and the liquid crystallinity and phase transition temperature determinedon DSC measurements, X-ray diffraction, and polarization microscopicanalyses. Table 3 shows the number average molecular weights and theweight average molecular weights, and the liquid crystallinity and phasetransition temperature with respect to the obtained polymers derivedfrom monomers having siloxane spacers. As is apparent from Table 2,these known homopolymers have higher glass transition temperatures and,as a result, higher temperature ranges at which the polymers exhibitliquid crystallinity than the corresponding copolymers obtained inExamples 1˜13. Therefore, it is apparent that the copolymerization witha monomer having a siloxane spacer shifts the temperature range ofliquid crystalline phase to lower temperature side. In addition, thecomparison of the results shown in Table 1 and 3 apparently indicatesthat the glass transition temperature of a copolymer of the presentinvention is close to that of a corresponding homopolymer having asiloxane spacer.

                  TABLE 2                                                         ______________________________________                                                                          Phase                                       Sample            Mn.sup.a)                                                                             Mw.sup.a)                                                                             transition                                  No.   Monomer     ×10.sup.-4                                                                      ×10.sup.-4                                                                      temp. (°C.)                          ______________________________________                                        HP-1  (4)         4.35    7.36    g 52 S 132 I                                HP-2  (5)         3.81    6.71    g 51 S 125 I                                HP-3  (6)         8.55    12.5    g 104 S 229 I                               HP-4  (7)         9.21    15.6    g 100 S 211 I                               HP-5  (8)         6.75    11.0    g 40 S* 58 S 112 I                          HP-6  (10)        0.346   0.469   g 10 N 99 I                                 ______________________________________                                         .sup.a) Mn; the number average molecular weight                               Mw; the weight average molecular weight                                       .sup.b) g; glass state, S; smectic phase                                      S*; chiral smectic phase, N; nematic phase,                                   I; isotropic phase                                                       

a) Mn; the number average molecular weight Mw; the weight averagemolecular weight b) g; glass state, S; smectic phase S*; chiral smecticphase, N; nematic phase, I; isotropic phase

                  TABLE 3                                                         ______________________________________                                                                          Phase                                       Sample            Mn.sup.a)                                                                             Mw.sup.a)                                                                             transition                                  No.   Monomer     ×10.sup.-4                                                                      ×10.sup.-4                                                                      temp. (°C.)                          ______________________________________                                        HP-7  (16)        4.93    9.88    g -3 I                                      HP-8  (20)        3.49    6.40    g 7 I                                       HP-9  (24)        2.12    4.44    g 33 S 144 I                                HP-10 (28)        2.37    4.38    g 42 S 164 I                                HP-11 (34)        0.428   0.541   g 8 I                                       HP-12 (38)        1.61    2.18    g 8 I                                       HP-13 (42)        3.05    4.44    g 19 S* 143 I                               HP-14 (43)        0.391   0.502   g -6 S 156 I                                ______________________________________                                         .sup.a) Mn; the number average molecular weight                               Mw; the weight average molecular weight                                       .sup.b) g; glass state, S; smectic phase                                      S*; chiral smectic phase, N; nematic phase,                                   I; isotropic phase                                                       

Industrial Applicability

The copolymer of the present invention contains a repeating unit havinga siloxane bond of high mobility in the spacer, whereby the glasstransition temperature is low at a level of room temperature or lower,and the copolymer exhibits stable liquid crystallinity in a widetemperature range from a relatively low temperature, i.e., at a roomtemperature or a lower temperature, as shown in Examples. Accordingly,the polymer having mesogenic groups of the present invention is usefulfor display materials, recording materials, or non-linear opticalmaterials in the electronics fields and for various other applicationssuch as light-controlling glass material or separating membranematerials in which its characteristics are advantageously utilized.

We claim:
 1. A copolymer having a mesogenic group in the side chaincomprising a repeating unit represented by the following formula (I):##STR26## wherein, R is a hydrogen atom, a halogen atom, an alkyl groupor a phenyl group, X is a single bond, an oxygen atom or a group of theformula --COO-- or --OCO--, Q¹ is a mesogenic group, and k is an integerof from 2 to 20, and a repeating unit represented by the followingformula (II): ##STR27## wherein, R', which may be the same or differentto the above R, is a hydrogen atom, a halogen atom, an alkyl group or aphenyl group, each of R¹ to R⁶, which may be the same or different, isan alkyl group or a phenyl group, X is a single bond, an oxygen atom ora group of the formula --COO-- or --OCO--, Q², which may be the same ordifferent to the above Q¹, is a mesogenic group, each of m and p is aninteger of from 2 to 10, and n is an integer of from 0 to 10; and themolar ratio of the repeating unit of the formula (I) to the repeatingunit of the formula (II) ranges from 95/5 to 20/80 and the numberaverage molecular weight is at least 1,000.
 2. A copolymer as defined inclaim 1, wherein the molar ratio of the repeating unit of the formula(I) to the repeating unit of the formula (II) ranges from 90/10 to40/60.